Plot fails with "center is not in (x,y) format"

[Nigel Malthus]

There seems to be a mistake in api.py which results in a "center is not in (x,y) format" error message when
the Plot class is called.
line 173 and 175:

    def __init__(self, pos, color=(0,0,0), size=1):
        try:
            self.center = make_it_a_point(center)

                                                                            ------'pos' in Line 173, but 'center' in Line 175.

    def __init__(self, pos, color=(0,0,0), size=1):
        try:
            self.center = make_it_a_point(pos)

                                                                           ---------fixes it.

[Rickard Westman (rwestman)]

Bug #1841477, filed before I noticed this bug report, provides more details about a recent reproduction of this bug reported in 2010. I also noticed that it is still unfixed as of 0.3.6, released in 2019.